Oral Pathobiont Streptococcus Anginosus Is Enriched in the Gut of Stroke Patients and Predicts 2-Year Cardiovascular...

Several cross-sectional studies have implicated gut dysbiosis caused by an abundance of oral commensals in stroke, but the effect on long-term prognosis is still unknown. Therefore, we longitudinally investigated oral pathobionts in the gut and their clinical relevance to stroke.

We analyzed the salivary and gut microbiomes collected from 189 acute stroke and 55 non-stroke subjects, and found that Streptococcus anginosus was significantly more abundant in both the saliva (median [IQR], 0.01 [0.00-0.14] vs. 0.00 [0.00-0.03], P=0.02) and gut (0.09 [0.00-0.28] vs. 0.00 [0.00-0.02], P<0.001) of the stroke patients compared with their non-stroke counterparts. Network analysis revealed S. anginosus as a central hub in gut dysbiosis. After adjusting for vascular risks, S. anginosus (odds ratio 1.20, 95% confidence interval 1.06-1.36, P<0.01), Anaerostipes hadrus (0.82, [0.73-0.93], P<0.01), and Bacteroides plebeius (0.86, [0.86-0.93], P=0.01) in the gut were independent predictors of stroke. Longitudinally, S. anginosus in the gut was significantly associated with increased rates of death and major cardiovascular events (P=0.04; log-rank test), whereas A. hadrus and B. plebeius were not (P=0.45 and P=0.19). After adjusting for vascular risks, S. anginosus in the gut was a residual risk for increased rates of death and major cardiovascular events (hazard ratio 4.78, 95% confidence interval 1.08-21.18, P=0.04)Conclusions: S. anginosus in the gut may increase the risk of stroke and a poor prognosis.